Ultrasound imaging of the pelvic floor. Part II: three-dimensional or volume imaging

Intrapartum translabial three-dimensional ultrasound visualization of levator trauma

OBJECTIVES

The aim of this study was to visualize levator trauma by three-dimensional (3D) ultrasound performed during labor and soon after the crowning of the fetal head and to determine how often levator trauma occurs.

METHODS

This was a prospective, observational study of 66 women enrolled during the first stage of labor. The women underwent intrapartum 3D transperineal ultrasound examination during the first and second stages of labor and within 12 h after delivery. Volume datasets were acquired and analyzed to determine the presence of levator trauma.

RESULTS

Data from 10 of the 66 women were excluded from analysis-nine because they underwent Cesarean section in the first or second stage of labor and one because she underwent hysterectomy and no postpartum volumes were collected. Thus our study group comprised 56 women-35 nulliparous and 21 parous. A total of 504 volumes were collected in the 56 women (three volumes for each stage of labor). One hundred and twenty levator volumes were excluded from analysis, but volumes of acceptable quality were available for all three stages of labor in all women. Eleven (31.4%) of the 35 nulliparae had levator lesions detected postpartum and none of them had levator lesions before delivery. Five (23.8%) of the 21 parous women had a levator tear detected in their postpartum volumes. In two of these five women the levator tear was also present in both volumes taken during labor.

CONCLUSIONS

Visualization of the levator ani during labor by 3D ultrasound examination is feasible. Comparison of volumes obtained during labor and within the first 2 h after delivery supports the theory that crowning of the head is the immediate cause of avulsion of the levator ani muscle.

Does levator ani injury affect cystocele type?

OBJECTIVE

To determine the prevalence of levator ani injury in patients with different types of cystocele, as defined by translabial ultrasound, in order to shed light on potential pathophysiological mechanisms.

METHODS

The datasets of 222 women who had undergone a physical examination, urodynamic testing and four-dimensional (4D) pelvic floor ultrasound were evaluated offline for prolapse, levator ani hiatal dimensions and levator ani trauma using tomographic ultrasound imaging (TUI), blinded against all clinical and urodynamic data. Cystoceles reaching below the symphysis pubis on ultrasound examination were classified based on bladder neck position, retrovesical angle (RVA) and urethral rotation as Green II (cystourethrocele) or Green III (cystocele with intact RVA).

RESULTS

Of 102 women who had a cystocele reaching below the symphysis pubis, 63 were classified as a Green type II cystocele and 39 as a Green type III cystocele. Women with Green type III cystoceles were older (59.4 vs. 48.7 years, P < 0.001), and had more severe prolapse (71 vs. 43%, P = 0.004) and objective voiding dysfunction (39 vs. 18%, P = 0.018). Women with Green III cystoceles also had larger hiatal dimensions and were more often diagnosed with an avulsion of the levator ani muscle (69 vs. 35%, P = 0.001).

CONCLUSION

A cystocele with an intact RVA is more likely to be associated with avulsion injury of the levator ani muscle and thus more likely to be caused by birth-related trauma. This contradicts the commonly held belief that such cystoceles are caused by central rather than by lateral fascial defects.

Unilateral coronal diameters of the levator hiatus: baseline data for the automated detection of avulsion of the levator ani muscle

OBJECTIVE

Levator ani avulsion injury is associated with pelvic organ prolapse. Although it can be detected by magnetic resonance imaging or translabial ultrasonography, both require substantial training. This retrospective study provides baseline measurements of the unilateral coronal or transverse diameter of the levator hiatus and assesses its use in the prediction of levator ani avulsion injury, as a step towards automated detection.

METHODS

Datasets of 787 patients seen in a tertiary urogynecological unit were assessed, including history, examination and three/four-dimensional pelvic floor ultrasound. Unilateral coronal diameters were measured off-line in stored volume datasets, with the operator blinded to clinical data. Volumes obtained during maximum pelvic floor muscle contraction were used, resorting to volumes obtained at rest for patients unable to contract their pelvic floor muscles.

RESULTS

Ultrasound images were available for 761 patients, including 16 (2.1%) who could not contract their pelvic floor muscles, generating 1522 unilateral measurements (both sides for 761 patients). Levator ani avulsion injury was associated with significant increase in the unilateral coronal diameter (2.57 +/- 0.5 vs. 2.1 +/- 0.3 cm, P < 0.0001). Receiver-operating characteristics curve analysis showed an area under the curve of 0.801 (95% CI, 0.765-0.837). A cut-off of 2.3 cm had a sensitivity of 71% and a specificity of 79% for the diagnosis of levator ani avulsion injury.

CONCLUSIONS

Levator ani avulsion injury is associated with a significant increase in unilateral coronal diameter, a cut-off point of 2.3 cm being most appropriate for alerting clinicians to a high likelihood of this diagnosis. It is hoped that this information will help to automate the detection of levator ani avulsion injury.

Intrapartum risk factors for levator trauma

OBJECTIVE

To determine intrapartum risk factors associated with levator trauma as identified by ultrasound imaging.

DESIGN

A prospective observational study.

SETTING

Antenatal clinic of a tertiary hospital between May 2005 and February 2008.

POPULATION

Nulliparous women (n=488) in their first ongoing pregnancy.

METHODS

An interview and four-dimensional translabial ultrasound was carried out between 36 and 38 weeks and again 3-4 months after delivery. Obstetric data were collected from the hospital database and/or participants' records.

MAIN OUTCOME MEASURES

Levator macrotrauma ('avulsion') and microtrauma (irreversible overdistension).

RESULTS

A total of 367 women (75%) returned for the postpartum assessment after normal vaginal delivery (n=187, 51%), vacuum (n=34, 9%), forceps (n=20, 5%) and caesarean section (n=126, 34%). Median follow up was 4.08 months (interquartile range 3.68-5.03 months). Levator avulsion was diagnosed in 32 (13%) of the women who delivered vaginally and in none of the caesarean section group regardless of indication. On multivariable regression forceps delivery was significantly associated with avulsion (P=0.01; OR 3.83; 95% CI 1.34-10.94). Using >20% peripartum increase in hiatal area on Valsalva as the cutoff, 28.5% of vaginally parous women were shown to have suffered irreversible overdistension. This was positively associated with the length of second stage (P=0.001; OR 1.01 per minute; 95% CI 1.0-1.02). Intrapartum epidural appeared to have a protective effect (P=0.03; OR 0.42; 95% CI 0.19-0.93).

CONCLUSION

Levator trauma at the time of first delivery is associated with vaginal delivery, forceps and a longer second stage. Epidural pain relief may exert a protective effect.

Application of 3-dimensional ultrasonography to imaging the fetal anal canal

OBJECTIVE

Ultrasonography has been applied previously to the assessment of the fetal anal canal. We aimed to examine the potential of 3-dimensional ultrasonography (3DUS) in the evaluation of the fetal anal canal and to obtain normal fetal anal canal measurements.

METHODS

Patients were recruited from an unselected population of gravidas with known gestational age (by dates or first-trimester ultrasonography) and without known fetal anomalies presenting for fetal evaluation in the ultrasound units of 2 tertiary care centers between 16 and 39 gestational weeks. In addition to the ordered scan, 3DUS imaging of the fetal anal canal was performed. Transverse and sagittal views and volumes were obtained. Measurements of the fetal anal canal anteroposterior diameter, lateral diameter, and length were performed in transverse and sagittal planes, respectively, and scatterplots of these dimensions were created. Measurements were performed and repeated on raw data sets by 2 independent observers, and the results were analyzed to estimate interobserver and intraobserver reliability.

RESULTS

A total of 186 patients were examined for this study at 16 to 39 weeks' gestation (mean, 27.4 weeks). The anteroposterior diameter of the fetal anal canal in this study group ranged from 4 to 21 mm (mean, 11.2 mm; SD, +/-3.5 mm), whereas the lateral diameter ranged from 7 to 18 mm (mean, 9.1 mm; SD, +/-3.0 mm). The length of the fetal anal canal in this study group ranged from 3 to 24 mm (mean, 14.3 mm; SD, +/-3.8 mm).

CONCLUSIONS

Ultrasonographic assessment of the fetal anal canal with 3DUS is feasible. Scatterplots were created for internal anal sphincter width and length measurements from 16 to 39 weeks' gestation. Larger studies are necessary to establish nomograms of these measurements and their application to the evaluation of pathologic cases. We speculate that 3DUS assessment of the fetal anal canal may improve detection rates of disorders involving this system.

The relationship between urethral mobility and parity

OBJECTIVE

Urethral mobility is associated with stress urinary incontinence (SUI) and urodynamic stress incontinence, and this is particularly true for mid-urethral mobility. The purpose of this study was to determine whether there is a significant relationship between segmental urethral mobility and vaginal parity in women undergoing urodynamic testing for prolapse or lower urinary tract symptoms.

DESIGN

Retrospective study. SETTING Tertiary referral service for multichannel urodynamic testing.

POPULATION

Women undergoing urodynamic testing for lower urinary tract symptoms or pelvic organ prolapse.

METHODS

The stored 3D translabial ultrasound volume data sets of 648 women were assessed. Measurements were performed using post-processing software in volumes obtained at rest and on maximal Valsalva manoeuvre. Analysis was based on a co-ordinate system using the dorsocaudal margin of the pubic symphysis. The urethral length was traced and divided into five equal segments. Mobility vectors are determined by the formula radical[(y(V) - y(R))(2) + (x(V) - x(R))(2)], where V indicates Valsalva and R indicates rest, with 'x' as the vertical distance and 'y' as the horizontal distance from the dorsocaudal margin of the pubic symphysis.

MAIN OUTCOME MEASURES

Mobility vector lengths.

RESULTS

The distal urethra is consistently the least mobile part of the organ, regardless of parity. Vaginal childbirth seems to increase urethral mobility by about 20% for all urethral segments (all P < or = 0.009). The first vaginal delivery showed the greatest effect, particularly on mid-urethral mobility.

CONCLUSIONS

There is a significant association between urethral mobility and vaginal delivery in women seen for symptoms of pelvic floor dysfunction, affecting all segments of the urethra equally. Most of this effect seems to result from the first vaginal birth.

Levator avulsion is a risk factor for cystocele recurrence

OBJECTIVES

To determine whether levator avulsion is a risk factor for recurrence after cystocele repair.

METHODS

This was an audit of women who underwent anterior colporrhaphy at a tertiary hospital between 2002 and 2005, who were followed up by interview, clinical examination and four-dimensional translabial ultrasound examination 3-6 years later.

RESULTS

Of 242 patients identified through theater records we were able to contact 171 (71%). Of 83 who agreed to attend, 24 (29%) reported symptoms of recurrent prolapse. There were 33 (40%) recurrent cystoceles (ICS POP-Q ≥ 0), [corrected] and 34 (41%) had a significant cystocele on ultrasound examination. On pelvic floor tomographic ultrasound examination, a levator avulsion was detected in 29 (35%) patients. The relative risk of recurrence in women with avulsion was 3.9 (95% CI, 2.4-5.8) when ultrasound criteria of recurrent cystocele were used, and 2.9 (95% CI, 1.7-4.5) when using clinical staging.

CONCLUSION

Levator avulsion is associated with a relative risk of 3-4 for cystocele recurrence after anterior colporrhaphy.

Imaging pelvic floor disorders: trend toward comprehensive MRI

OBJECTIVE

The purpose of this article is to review the relevant anatomy and sonographic, fluoroscopic, and MRI options for evaluating patients with pelvic floor disorders.

CONCLUSION

Disorders of the pelvic floor are a heterogeneous and complex group of problems. Imaging can help elucidate the presence and extent of pelvic floor abnormalities. MRI is particularly well suited for global pelvic floor assessment including pelvic organ prolapse, defecatory function, and pelvic floor support structure integrity.

Validation of three-dimensional perineal ultrasound and magnetic resonance imaging measurements of the pubovisceral muscle at rest

OBJECTIVE

To compare biometric measurements of the pubovisceral muscle during rest, measured using transperineal three-dimensional (3D) ultrasound and magnetic resonance imaging (MRI).

METHODS

In this prospective study, 18 female volunteers underwent 3D perineal ultrasound examination and MRI. All women were examined at rest in the supine position and the following measurements were taken: area and anteroposterior and transverse diameters of the levator hiatus; thickness of the pubovisceral muscle, measured lateral to the vagina and to the rectum, on the right and left sides; length of the levator-urethra gap (LUG), measured from the center of the urethra to the insertion of the pubovisceral muscle on the pubic bone. Interclass correlation coefficients (ICC) between the measurements obtained with 3D ultrasound and with MRI were calculated. To quantify the intermeasurement agreement, the bias and SDs were calculated, and limits of agreement constructed. One investigator performed all the analyses.

RESULTS

There was no significant difference between the mean values of the measurements by 3D perineal ultrasound and those by MRI. The ICC values showed very good agreement (range, 0.80-0.97). There was a significant positive bias for LUG on the left side and muscle thickness on the right side of the vagina.

CONCLUSION

These results suggest that 3D ultrasound could be used instead of MRI when evaluating static pelvic floor anatomy in women without pelvic organ prolapse at rest.

Assessment of posterior compartment prolapse: a comparison of evacuation proctography and 3D transperineal ultrasound

INTRODUCTION

Evacuation proctography (EP) is considered to be the gold standard investigation for the diagnosis of posterior compartment prolapse. 3D transperineal ultrasound (3DTPUS) imaging of the pelvic floor is a noninvasive investigation for detection of pelvic floor abnormalities. This study compared EP with 3DTPUS in diagnosing posterior compartment prolapse.

METHOD

In a prospective observational study, patients with symptoms related to posterior compartment prolapse participated in a standardized interview, clinical examination, 3DTPUS and EP. Both examinations were analysed separately by two experienced investigators, blinded against the clinical data and against the results of the other imaging technique. After the examinations, all patients were asked to fill out a standardized questionnaire concerning their subjective experience.

RESULTS

Between 2005 and 2007, 75 patients were included with a median age of 59 years (range 22-83). The Cohen's Kappa Index for enterocole was 0.65 (good) and for rectocele it was 0.55 (moderate). The level of correlation for intussusception was fair (kappa = 0.21).

CONCLUSION

This study showed moderate to good agreement between 3DTPUS and EP for detecting enterocele and rectocele.

Can levator avulsion be predicted antenatally?

OBJECTIVE

We sought to determine whether antepartum prediction of major levator trauma is feasible.

STUDY DESIGN

A prospective longitudinal study was undertaken on 488 pregnant nulliparous women seen between 36-38 weeks and again 4 months after delivery. All underwent an interview and 4-dimensional transperineal ultrasound. Diagnosis of levator trauma (avulsion) on tomographic ultrasound was correlated with predelivery demographic variables and ultrasound parameters.

RESULTS

In all, 367 women returned for postpartum assessment after normal vaginal delivery (n = 187), vacuum/forceps (n = 54), and cesarean section (n = 126). Avulsion was diagnosed in 34 vaginally parous women (14%). Maternal age, family history of cesarean section, hiatal dimensions, levator muscle strain, bladder neck descent, and subpubic arch angle were not associated with avulsion. The only predictor identified was a lower body mass index (P = .005).

CONCLUSION

Antepartum prediction of major levator trauma may be difficult or impossible. Future studies should focus on modification of current obstetric practices and antepartum interventions applicable to the general population.

Three-dimensional ultrasound imaging

This review is about the development of three-dimensional (3D) ultrasonic medical imaging, how it works, and where its future lies. It assumes knowledge of two-dimensional (2D) ultrasound, which is covered elsewhere in this issue. The three main ways in which 3D ultrasound may be acquired are described: the mechanically swept 3D probe, the 2D transducer array that can acquire intrinsically 3D data, and the freehand 3D ultrasound. This provides an appreciation of the constraints implicit in each of these approaches together with their strengths and weaknesses. Then some of the techniques that are used for processing the 3D data and the way this can lead to information of clinical value are discussed. A table is provided to show the range of clinical applications reported in the literature. Finally, the discussion relating to the technology and its clinical applications to explain why 3D ultrasound has been relatively slow to be adopted in routine clinics is drawn together and the issues that will govern its development in the future explored.

Is sacral neuromodulation for fecal incontinence worthwhile in patients with associated pelvic floor injury?

PURPOSE

It has been shown that vaginal delivery may result in pelvic floor injury. Until now it is unknown whether this type of injury plays a role in the etiology of fecal incontinence and whether it affects the outcome of treatment. The aim of the present study was to assess the prevalence of pelvic floor injury in patients with fecal incontinence who were eligible for sacral neuromodulation and to determine whether sacral neuromodulation is worthwhile in patients with pelvic floor injury.

METHODS

All women with fecal incontinence who were eligible for sacral neuromodulation in the past were invited to participate in the present study. With transperineal ultrasound, which has been developed recently, pelvic floor integrity was examined in 46 of the 66 patients (70%). Follow-up was obtained from a standardized questionnaire.

RESULTS

Pelvic floor injury was found in 29 of the 46 participants (63%). No differences regarding the efficacy of sacral neuromodulation were found between patients with and those without pelvic floor injury. Successful test stimulation was obtained in 86% of the patients with pelvic floor injury and in 71% of the patients without pelvic type injury. After implantation of a definitive pulse generator, a successful outcome was found in 84% of the patients with pelvic floor injury and in 75% of the patients with an intact pelvic floor.

CONCLUSION

Pelvic floor injury is present in the majority of incontinent patients who were eligible for sacral neuromodulation. This type of injury seems to have no detrimental effect on the treatment outcome.

Pelvic floor ultrasound: a review

Imaging currently plays a limited role in the investigation of pelvic floor disorders. It is obvious that magnetic resonance imaging has limitations in urogynecology and female urology at present due to cost and access limitations and due to the fact that it is generally a static, not a dynamic, method. However, none of those limitations apply to sonography, a diagnostic method that is very much part of general practice in obstetrics and gynecology. Translabial or transperineal ultrasound is helpful in determining residual urine; detrusor wall thickness; bladder neck mobility; urethral integrity; anterior, central, and posterior compartment prolapse; and levator anatomy and function. It is at least equivalent to other imaging methods in visualizing such diverse conditions as urethral diverticula, rectal intussusception, mesh dislodgment, and avulsion of the puborectalis muscle. Ultrasound is the only imaging method able to visualize modern mesh slings and implants and may predict who actually needs such implants. Delivery-related levator trauma is the most important known etiologic factor for pelvic organ prolapse and not difficult to diagnose on 3-/4-dimensional and even on 2-dimensional pelvic floor ultrasound. It is likely that this will be an important driver behind the universal use of this technology. This review gives an overview of the method and its main current uses in clinical assessment and research.

The urethral motion profile before and after suburethral sling placement

PURPOSE

We examined the effect of the Monarc suburethral sling on urethral mobility.

MATERIALS AND METHODS

We retrospectively studied the records of 54 consecutive women who received a Monarc suburethral sling between July 2005 and November 2008. All patients were examined by volume ultrasound preoperatively and at followup (average 0.7 years). Volume data sets were analyzed using post-processing software. Urethral mobility was described by vectors of movement from rest to a maximum Valsalva maneuver of 6 equidistant points marked evenly along the urethra from bladder neck (point 1) to external urethral meatus (point 6), as identified in the mid sagittal view. Measurements were made of point coordinates relative to the pubic symphysis dorsocaudal margin at rest and during maximal Valsalva maneuver. To determine the urethral motion profile we calculated mobility vectors of the 6 points using the formula, square root [(x(val) - x(rest))(2) + (y(val) - y(rest))(2)], where val represents the value during the Valsalva maneuver and rest represents the value at rest. We compared values before and after sling placement.

RESULTS

The subjective cure rate for stress urinary incontinence was 78% (42 cases). There was a statistically significantly decreased mobility at points 2 to 4, corresponding to the urethral central aspect (p = 0.002 to 0.018). No significant change in mobility was noted at the bladder neck and distal urethra (p = 0.39 to 0.89).

CONCLUSIONS

Monarc suburethral sling placement decreases mid urethral mobility but does not seem to affect the bladder neck.

Anterior sphincteroplasty for fecal incontinence: is the outcome compromised in patients with associated pelvic floor injury?

INTRODUCTION

It has been shown that vaginal delivery may result not only in sphincter defects, but also in pelvic floor injury. However, the influence of this type of injury on the etiology of fecal incontinence and its treatment is unknown. The present study was aimed to assess the prevalence of pelvic floor injury in patients who underwent anterior sphincteroplasty for the treatment of fecal incontinence and to determine the impact of this type of injury on the outcome of this procedure.

METHODS

Women who underwent anterior sphincteroplasty in the past were invited to participate in the present study. With transperineal ultrasound, which has been developed recently, pelvic floor integrity was examined in 70 of 117 patients (60%). Follow-up was obtained from a standardized questionnaire.

RESULTS

The median time period between anterior sphincteroplasty and the current assessment was 106 (range, 15-211) months. Pelvic floor injury was diagnosed in 43 patients (61%). Despite the prior sphincteroplasty, an external anal sphincter defect was found in 20 patients (29%). Outcome did not differ, neither between patients with and those without pelvic floor injury, nor between patients with and those without an adequate repair. However, patients with an adequate repair and an intact pelvic floor did have a better outcome than patients with one or both abnormalities.

CONCLUSION

The majority of female patients with incontinence who were eligible for anterior sphincteroplasty have concomitant pelvic floor injury. Based on the present study, it seems unlikely that this type of injury itself has an impact on the outcome of anterior sphincteroplasty.

Dynamic magnetic resonance imaging and transperineal sonography in the assessment of patients presenting primarily with evacuatory difficulty: a short position paper

Patients presenting with primary evacuatory difficulty have a multiplicity of pelvic floor and perineal soft tissue anomalies. The radiological assessment of these patients requires modalities which monitor the dynamic interaction of pelvic organs during provocative manoeuvres such as straining and simulated defaecation. The advantages and disadvantages of these complementary modalities, (dynamic magnetic resonance imaging, dynamic transperineal sonography and dynamic 2- and 3-dimensional endoanal sonography) are provided in this position paper.

The effect of levator avulsion on hiatal dimension and function

OBJECTIVE

Pelvic floor trauma as a result of vaginal childbirth can cause significant pelvic floor morbidity. In this observational study, we intended to define whether such trauma is associated with abnormal hiatal biometry and/or abnormal biomechanical properties of the levator muscle.

STUDY DESIGN

The datasets of 414 urogynecologic patients were assessed in a retrospective study. Patients underwent an interview, clinical examination, and 3-/4-dimensional pelvic floor ultrasound. All analysis was performed offline using proprietary software. Hiatal dimensions and strain were measured.

RESULTS

In 21.1% of parous women with a history of vaginal delivery, an avulsion of the levator muscle was diagnosed, and in 8.6% it was bilateral. The relative risk of abnormal distensibility was 3.5 (95% confidence interval, 1.7-6.5) in unilateral and 3.96 (95% confidence interval, 1.7-9.2) in bilateral avulsion. Avulsion increased muscle distensibility on Valsalva and reduced muscle shortening on pelvic floor muscle contraction.

CONCLUSION

Avulsion injury is associated with abnormal levator biometry and function.

Tomographic ultrasound imaging of the pelvic floor: which levels matter most?

OBJECTIVES

Tomographic ultrasound imaging has greatly simplified pelvic floor assessment. Abnormalities of the insertion of the levator ani can be documented in a single frame. In this study we aimed to determine which levels of the levator hiatus are associated with alterations in ultrasound parameters of pelvic organ support.

METHODS

This was a subanalysis of a study conducted in 296 women seen before and after their first delivery. We analyzed postpartum changes in bladder neck descent and hiatal area as indicators of altered pelvic organ support. Tomographic ultrasound examination was performed on volumes obtained at maximal pelvic floor muscle contraction, at 2.5-mm slice intervals, from 5 mm below to 12.5 mm above the plane of minimal hiatal dimensions.

RESULTS

Two hundred and eight recruits (70%) returned for a postnatal appointment. Of these, 130 had delivered vaginally and 26 (20%) were diagnosed with an avulsion injury. An abnormality in slices 3-8 was associated with increased bladder neck descent postpartum (P = 0.038 to P = 0.001) and increased hiatal area on Valsalva maneuver (P = 0.029 to P < 0.001). This was not the case for the two most distal slices.

CONCLUSIONS

We found no association between levator ani defects observed on tomographic ultrasound imaging below the plane of minimal hiatal dimensions and indices of increased hiatal distension or bladder neck descent on Valsalva maneuver. This implies that defects observed below this plane are either irrelevant for pelvic organ support or artifactual.

Interobserver repeatability of three- and four-dimensional transperineal ultrasound assessment of pelvic floor muscle anatomy and function

OBJECTIVE

To evaluate the interobserver repeatability of measurement of the pubovisceral muscle and levator hiatus, and the position of related organs, during rest, muscle contraction and Valsalva maneuver using three- and four-dimensional (3D and 4D) transperineal ultrasound.

METHODS

Seventeen women were included in the study. The position and dimensions of the pubovisceral muscle and levator hiatus in patients at rest and during contraction and Valsalva were determined from stored 3D and 4D ultrasound volumes. Analyses were conducted offline by two observers blinded to the clinical data and to each others' measurements.

RESULTS

Measurements of levator hiatal dimensions at rest demonstrated intraclass correlation coefficient (ICC) values of 0.92 to 0.96. The ICC values for pubovisceral muscle thickness at rest varied between good and very good (ICC, 0.61-0.93), regardless of plane. During contraction, the ICC values for all measured parameters were very good, varying between 0.61 and 0.92. Measurement of the transverse diameter of the levator hiatus during the Valsalva maneuver showed good reliability (ICC, 0.86), but assessment of the anterior and posterior borders of the levator hiatus was only possible in 29% of cases.

CONCLUSIONS

3D and 4D transperineal ultrasound measurement of the pubovisceral muscle and levator hiatus is reliable in women with no or minor symptoms of prolapse at rest and during contraction. The technique for recording during the Valsalva maneuver requires improvement if it is to be useful in the diagnosis of pelvic organ prolapse.

Dynamics of female pelvic floor function using urodynamics, ultrasound and Magnetic Resonance Imaging (MRI)

In this review the diagnostic potential of evaluating female pelvic floor muscle (PFM) function using magnetic and ultrasound imaging in the context of urodynamic observations is considered in terms of determining the mechanisms of urinary continence. A new approach is used to consider the dynamics of PFM activity by introducing new parameters derived from imaging. Novel image-processing techniques are applied to illustrate the static anatomy and dynamics of PFM function of stress incontinent women pre- and post-operatively as compared to asymptomatic subjects. Function was evaluated from the dynamics of organ displacement produced during voluntary and reflex activation. Technical innovations include the use of ultrasound analysis for movement of structures during maneuvers that are associated with external stimuli. Enabling this approach is the development of criteria and fresh and unique parameters that define the kinematics of PFM function. Principal among these parameters, are displacement, velocity, acceleration and the trajectory of pelvic floor landmarks. To accomplish this objective, movement detection, including motion tracking algorithms and segmentation algorithms were developed to derive new parameters of trajectory, displacement, velocity and acceleration, and strain of pelvic structures during different maneuvers. Results highlight the importance of timing the movement and deformation to fast and stressful maneuvers, which are important for understanding the neuromuscular control and function of PFM. Furthermore, observations suggest that timing of responses is a significant factor separating the continent from the incontinent subjects.

PELVIC FLOOR ASSESSMENT

The topic of pelvic floor assessment is increasingly attracting attention from gynaecologists, colorectal surgeons, urologists and physiotherapists. This is not surprising, many women who have given birth naturally are affected by pelvic floor trauma, and so are their partners. Health professionals deal with the eventual consequences of such trauma, especially pelvic organ prolapse and faecal incontinence.

Pelvic floor anatomy and applied physiology

Pelvic floor muscles have two major functions: they provide support or act as a floor for the abdominal viscera including the rectum; and they provide a constrictor or continence mechanism to the urethral, anal, and vaginal orifices (in females). This article discusses the relevance of pelvic floor to the anal opening and closure function, and discusses new findings with regards to the role of these muscles in the vaginal and urethra closure mechanisms.

3D Ultrasound in Gynecology and Reproductive Medicine

With advances occurring in medicine on a daily basis, it was only a matter of time before essential gynecological investigations, such as ultrasound, were modified. Many clinicians remain unconvinced by its reputed advantages and 3D ultrasound is not without disadvantages. These mainly relate to the cost implications and training requirements. 3D ultrasound imaging is still at a relatively early stage in terms of its role as a day-to-day imaging modality in gynecology and reproductive medicine. 3D imaging has several obvious benefits that relate to an improved spatial orientation and the demonstration of multiplanar views, of which the coronal plane is particularly useful. It offers a more objective and reproducible measurement of volume and vascularity of the region of interest, and an improved assessment of normal and pathological pelvic organs through further postprocessing modalities, including tomographic ultrasound imaging and various rendering modalities. It also has the benefit of offering reduced scanning time, the option of teleconsultation and storage of images for re-evaluation. However, other than its application in the assessment and differentiation of uterine anomalies, there is very little evidence demonstrating that 3D ultrasound results in a clinically relevant benefit or negates the need for further investigation. Future work should ensure that 3D ultrasound is compared with conventional imaging in randomized trials where the observer is blind to the outcome, only after which will we truly be able to evaluate its role in an evidence-based manner.

Transobturator mesh for cystocele repair: a short- to medium-term follow-up using 3D/4D ultrasound

OBJECTIVE

Anterior colporrhaphy has been shown to have limited medium-term success rates in cystocele repair. Many clinicians use mesh implants, but their safety and efficacy are controversial. We therefore performed an external surgical audit using three- and four-dimensional pelvic floor ultrasound to study the short- to medium-term results of transobturator mesh placement.

METHODS

Forty-six women who had undergone transobturator mesh anterior repair using the Perigee(TM) system were invited back for a follow-up appointment conducted by two non-surgeons. The appointment consisted of a standardized interview, clinical examination using the International Continence Society Pelvic Organ Prolapse Quantification system (ICS POP-Q) and translabial ultrasound examination.

RESULTS

The mean follow-up time was 10 (range, 2-24) months. There had been no major intra- or postoperative complications. Thirty-six (78%) patients were subjectively satisfied with the outcome of the procedure. Cystocele recurrence (Stage 2 or 3) was observed in six (13%) patients. There were three (6.5%) cases of mesh erosion. On translabial ultrasound, we observed cystocele recurrence dorsal to the mesh in five women, associated with a marked change in mesh axis on Valsalva, implying dislodgment of the superior anchoring arms. The mesh was measured at a mean of 21 (range, 8.8-37.3; SD, 7.0) mm in length.

CONCLUSIONS

At 10-month follow-up the Perigee procedure seems to be safe and effective for cystocele repair, with a satisfaction rate of 78%. In some women recurrence may occur due to dislodgment of the superior anchoring arms.

Pelvic organ prolapse symptoms in relation to POPQ, ordinal stages and ultrasound prolapse assessment

Adequate staging of pelvic organ prolapse is important in clinical practice and research. The ability of the POPQ, ordinal stages and ultrasound prolapse assessment were evaluated for their ability to discriminate between women with and without prolapse symptoms. The leading edge of the predominant compartment in the three assessment systems was used for the calculation of receiver operating characteristics curves. Two hundred and sixty five (265) consecutive women were evaluated. The area under the receiver operating characteristics curve for the three staging systems ranged from 0.715 to 0.783. POPQ staging and ordinal staging performed equally well in the prediction of prolapse symptoms (p = 0.780), and both performed better as compared with ultrasound prolapse assessment (p = 0.048 and p = 0.015, respectively). Prolapse staging can equally be performed by the POPQ and ordinal stages systems as far as the discrimination between women with and without prolapse symptoms is concerned. The ultrasound prolapse assessment does not perform better as compared with these two systems.

Defecation proctography and translabial ultrasound in the investigation of defecatory disorders

OBJECTIVES

Defecation proctography is the standard method used in the investigation of obstructed defecation. Translabial ultrasound has recently been shown to demonstrate rectocele, enterocele and rectal intussusception. We performed a comparative clinical study to determine agreement between the two methods.

METHODS

Thirty-seven women scheduled to undergo defecation proctography for obstructed defecation were recruited. Using both proctography and translabial ultrasound, we determined the anorectal angle, presence of a rectocele and rectocele depth, rectal intussusception and prolapse. Measurements were obtained by operators blinded to all other data. All patients rated discomfort on a scale of 0-10.

RESULTS

Six women did not attend defecation proctography, leaving 31 cases for comparison. The mean age was 53 years. Patients rated discomfort at a median of 1 (range 0-10) for ultrasound and 7 (range 0-10) for defecation proctography (P < 0.001). Defecation proctography suggested rectocele and rectal intussusception/prolapse more frequently than did ultrasound. While the positive predictive value of ultrasound (considering defecation proctography to be the definitive test) was 0.82 for rectocele and 0.88 for intussusception/prolapse, negative predictive values were only 0.43 and 0.27, respectively. Cohen's kappa values were 0.26 and 0.09, respectively. There was poor agreement between ultrasound and defecation proctography measurements of anorectal angle and rectocele depth.

CONCLUSIONS

Translabial ultrasound can be used in the initial investigation of defecatory disorders. It is better tolerated than defecation proctography and also yields information on the lower urinary tract, pelvic organ prolapse and levator ani. Agreement between ultrasound and defecation proctography in the measurement of quantitative parameters was poor, but when intussusception or rectocele was diagnosed on ultrasound these results were highly predictive of findings on defecation proctography.

[Role of ultrasound in the evaluation of patients after laparoscopic sacropexy: preliminary study]

OBJECTIVES

To evaluate results of laparoscopic sacropexy with introital and vaginal ultrasonography, that is to observe dynamic behavior of the mesh, to measure precisely its position and to conclude on the feasibility of this exam.

PATIENTS AND METHODS

The surgery was a laparoscopic subtotal hysterectomy and a suspension of the cervix with an anterior vesicovaginal mesh and a posterior rectovaginal mesh. These meshes are joined together and fixed on the sacrum. Ultrasound was performed in fifteen patients to see in the sagital plane the position of the mesh. The distance anterior mesh-bladder neck and the distance posterior mesh-anal sphincter were measured at rest, during straining and during retaining. The spreading out and the dynamic behavior of the mesh were studied.

RESULTS

The distance anterior mesh-bladder neck is 12 mm at rest, 15 mm during straining and 13 mm during retaining. The distance posterior mesh-anal sphincter is 30 mm at rest, 26 mm during straining and 31 mm during retaining. The mesh is always seen as spread out, or folded, but never strained. Video recording shows that sacropexy does not block pelvic dynamics.

DISCUSSION AND CONCLUSION

Ultrasound imaging appears in this study as a simple and efficient exam to study and measure prosthesis. It could be a good help for clinical examination to explain failure or complication of surgery.

Validity and reproducibility of the digital detection of levator trauma

Levator ani muscle trauma is a common consequence of vaginal childbirth and detectable on digital vaginal palpation. To ascertain validity and reproducibility of this test, we saw 110 women for an interview, prolapse staging, digital vaginal palpation by two blinded examiners and four-dimensional translabial ultrasound. The mean age was 55.5 years (range 17-85) and the median parity was 2 (range 0-8). Three patients could not be assessed, leaving 107 datasets representing 214 assessments of a right or left puborectalis muscle. Levator defects were found in 21 women (20%) with nine bilateral defects. There was agreement between assessors in 173/214 (81%), k=0.411, signifying moderate agreement. Agreement with an independent blinded review of tomographic ultrasound data was k=0.495. Even after substantial training, the agreement between assessors using digital palpation for the diagnosis of levator trauma remains only moderate. There seems to be a substantial learning curve. Palpatory detection of major levator trauma is less repeatable than identification by ultrasound.